Due to its excellent material properties, gallium nitride and other hetero-structures of the III-V material group are candidates for fabricating semiconductor devices with high performance, for example, with respect to the temperature stability, the operation speed or the breakdown voltage. The III-V semiconductor devices can, for example, be used as power semiconductor devices or in high frequency applications.
A prerequisite for manufacturing III-V semiconductor devices with high performance is, among others, a sufficient quality of the epitaxially grown III-V semiconductor material layers. The growth of, for example, gallium nitride (GaN) on silicon (Si) may often result in low-quality GaN layers, which are not suitable to form semiconductor devices. The low-quality III-V material layers may comprise a high number of defects, e.g., slip lines and other distortions of the grown crystal lattice. The dislocation defects or slip lines may be formed during the epitaxial growth of the crystal. The slip lines may emerge at the silicon substrate. Thereby the slip lines can grow only partially through the epitaxial layer or through the whole epitaxial layer. Such an epitaxial layer with a high number of dislocation defects may be unsuitable for a further processing of a semiconductor device.